Glossary
Nautical chart abbreviations are like the secret code of the seas—except instead of buried treasure, they lead to rocks, buoys, and mysterious dashed lines that scream, 'Don’t sail here.' Learning them can feel like cracking a pirate’s encrypted diary, but don’t worry, matey! With clever tools, quirky mnemonics, and a splash of humour, we’ll help you go from 'What’s "FOUL" mean? to confidently navigating the “Wk” wrecks and “Fl G” flashes like a salty sea captain. Think of it as Rosetta Stone, but for avoiding sandbanks!
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TermDefinition
- Flag Semaphore, Signals & Communication Number 2 (Flag Semaphore)
Flag semaphore indicating the number 2. This shape is the Number 2 (Flag Semaphore) and the Letter B (Flag Semaphore).
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More Details - Flag Semaphore, Signals & Communication Number 3 (Flag Semaphore)
Flag semaphore indicating the Number 3. This shape represents both the Number 3 (Flag Semaphore) and the Letter C (Flag Semaphore).
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More Details - Flag Semaphore, Signals & Communication Number 4 (Flag Semaphore)
Flag semaphore indicating the Number 4. This shape represents both the Number 4 (Flag Semaphore) and the Letter D (Flag Semaphore).
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More Details - Flag Semaphore, Signals & Communication Number 5 (Flag Semaphore)
Flag semaphore indicating the Number 5. This shape represents both the Number 5 (Flag Semaphore) and the Letter E (Flag Semaphore).
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More Details - Flag Semaphore, Signals & Communication Number 6 (Flag Semaphore)
Flag semaphore indicating the Number 6. This shape represents both the Number 6 (Flag Semaphore) and the Letter F (Flag Semaphore).
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More Details - Flag Semaphore, Signals & Communication Number 7 (Flag Semaphore)
Flag semaphore indicating the Number 7. This shape represents both the Number 7 (Flag Semaphore) and the Letter G (Flag Semaphore).
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More Details - Flag Semaphore, Signals & Communication Number 8 (Flag Semaphore)
Flag semaphore indicating the Number 8. This shape represents both the Number 8 (Flag Semaphore) and the Letter H (Flag Semaphore).
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More Details - Flag Semaphore, Signals & Communication Number 9 (Flag Semaphore)
Flag semaphore indicating the Number 9. This shape represents both the Number 9 (Flag Semaphore) and the Letter I (Flag Semaphore).
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More Details - Flag Semaphore, Signals & Communication Numerals--Numbers Follow (Flag Semaphore)
This flag semaphore signal indicates a change from letters to numbers (Numbers Follow), indicating that the signaller will be using the numeric...
More Details - Abbreviation, Light Characteristic Oc
A light with more light than dark (is on for longer than it is off).
Occulting refers to a type of navigational light in which the light is...
More Details - Abbreviation, Light Characteristic Occulting (Oc)
A light with more light than dark (is on for longer than it is off).
Occulting refers to a type of navigational light in which the light is...
More Details - General Nautical Terminology Ocean Data Acquisition System (ODAS)
The Ocean Data Acquisition System (ODAS) is a system used to collect, process, and transmit various types of oceanographic data. This system...
More Details - General Nautical Terminology ODAS
The Ocean Data Acquisition System (ODAS) is a system used to collect, process, and transmit various types of oceanographic data. This system...
More Details - Phonetic Alphabet Oscar
Phonetic alphabet letter O.
Meaning: The Oscar flag signals "Man overboard." Often seen on the top of a Danbouy MOB recovery...
More Details - General Nautical Terminology Overhand loop
A loop that crosses on top of the standing part of a rope when tying a knot.
- Phonetic Alphabet Papa
Phonetic alphabet letter P.
Departure Signal: When a vessel displays the Papa flag, it signals to all personnel ashore that they should return...
More Details - General Nautical Terminology Passage
A passage describes a vessel's entire journey from start to end. Every passage should have a passage plan outlining the vessel's intentions and...
More Details - General Nautical Terminology PDOP
Position Dilution of Precision (PDOP) measures the geometric strength of satellite configuration in a Global Navigation Satellite System (GNSS)...
More Details - Phonetic Alphabet, Signals & Communication Phonetic Alphabet
The Phonetic Alphabet, also known as the International Radiotelephony Spelling Alphabet or NATO phonetic alphabet, is a standardised set of words...
More Details - General Nautical Terminology Pontoon
A pontoon is a flat, buoyant structure used to support a platform, bridge, or boat. It is typically made of metal, plastic, or inflatable...
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